This is the Annozilla project, designed to view and
create annotations associated with a web page, as defined by the W3C Annotea project. The idea is to
store annotations as RDF on a server, using XPointer (or at least XPointer-like
constructs) to identify the region of the document being annotated.

The intention of Annozilla is to use Mozilla's native facilities to
manipulate annotation data - its built-in RDF handling to parse the
annotations, and nsIXmlHttpRequest to submit data when creating
annotations.